1. Field of the Invention
The present invention relates to mechanical guns, and more particularly to a novel such gun in which one or more cartridges, each comprising a barrel and a projectile, are sequentially discharged by compressed air delivered from a single air pump assembly.
2. Brief Description of the Prior Art
Single shot toy airguns have been in common use for many years in which a spring operated piston forces air from a chamber and through a barrel to eject a projectile from the barrel (for example, Cagan et al., 4,212,285). More recently, toy airguns have been developed for launching multiple projectiles between loadings, such as Ferri (4,841,655) and Tsao (4,848,307). Difficulties and disadvantages are encountered with the aforementioned designs stemming from the methods of engagement of the airpump with the launching barrels for transfer of compressed air to the projectiles.
Tsao ('307) provides a single airpump for propelling projectiles from a plurality of barrels in a rotating magazine, but provides no air seal between the airpump outlet 401 and barrels 21, and requires a special projectile having an internal air chamber 84 and funnel shaped tail 82 to catch an airstream from the airpump. This allows for significant amounts of air and hence propelling force to be lost in the gap between the airpump outlet 401 and the projectile 8.
Ferri ('655) provides a constant spring bias 14 within a two piece projectile magazine 12A, 12C of expandable length whereby the magazine is always in tight engagement between the gun frame on its forward end and the airpump outlet 18A on its rearward end. This arrangement provides a seal between the magazine chambers 16 and the airpump outlet 18A but yields the undesirable side effect of high friction between the magazine and frame during advancement of the magazine, thus requiring sturdier construction and greater force for operation of the gun. The two effects oppose one another, whereby adjustment of the magazine bias to give a strong air seal generates a gun which is more difficult to operate while adjustment for ease of operation yields a gun with a poor airseal.